The love/hate with food

I dont like complaining about this pregnancy as it has answered all my hopes and dreams after my miscarriage. But the wierd relationship with food thing is starting to seriously effect my mood and life! I get little to no warning of hunger pains coming, its like one minute im full and satified the next im painfully starving hungry. When i feel like this i only fancy a small number of things and im so bad tempered as im in pain i find it hard to go and shop or cook for these foods! If my hunger isnt satisfied quickly thats when the sickness starts. This is my 4th pregnancy and ive never had this before! Anyone else have this?